圆锥形中空夹层钢管混凝土偏压构件受力性能研究

将圆锥形中空夹层钢管混凝土用于风电塔筒或输电塔架时，为满足在塔筒内设置设备等需求而将该类构件空心部分加大。为研究该类构件的偏压受力性能，进行了12个大空心率下的圆锥形中空夹层钢管混凝土偏心受压构件的试验研究，主要试验参数为荷载偏心率和长细比。利用ABAQUS软件建立有限元分析模型，对圆锥形中空夹层钢管混凝土偏心受压构件的典型破坏模态和荷载-变形关系曲线进行模拟，所得计算结果与试验结果基本吻合。通过典型算例分析了受力过程中钢管和混凝土各自所承担的荷载和纵向应力分布情况，同时分析了内、外钢管与混凝土之间相互作用力的变化情况。结果表明：偏心率和长细比对圆锥形中空夹层钢管混凝土偏心受压构件承载力及刚度有显著影响；该类构件力学行为与等截面圆中空夹层钢管混凝土偏心受压构件类似，锥度的存在使破坏位置从等截面柱的中部上移到锥形柱的3/4柱高处(柱顶处)，因此在设计大空心率圆锥形中空夹层钢管混凝土偏压(压弯)构件时应考虑柱头处加强。同时，对该类构件压弯承载力计算方法给出了建议。

Research on mechanical behavior of tapered concrete-filled double skin steel tubular members under eccentric compression

When the tapered concrete-filled double skin steel tube (CFDST) is used in the construction of wind power tower or transmission tower, the hollow part of this component is often designed to be larger to meet the installation requirement of equipment. To study the mechanical performance of this component, twelve specimens with large hollow ratios under eccentric compression were tested, and the test parameters were load eccentricity ratio and slenderness ratio. The software ABAQUS was used to establish the finite element analysis(FEA) model to simulate the typical failure modes and load-deformation curves of tapered CFDST members under eccentric compression, and the calculated results were consistent with the experimental results. The load distribution and longitudinal stress of steel tubes and concrete were investigated through a typical case. Meanwhile, the interaction between steel tubes and infilled concrete was also analyzed. The results show that load eccentricity ratio and slenderness ratio have a significant influence on the bearing capacity and stiffness of specimens. The mechanical behavior of tapered CFDST members is similar to that of the common CFDST members with constant section. The tapered CFDST specimens fail at the section at 3/4 of the column height, while specimens with constant section fails at the middle section owing to the tapered angle. Therefore, in the design of tapered CFDST members with a large hollow ratio, strengthening at the column head should be considered. Meanwhile, the calculation method of bearing capacity of tapered CFDST members was proposed.